Engine



J. D. MQCLACHLAN ENGINE Sep. 11, E923. 11945173@ Original Filed Sent. '7. 1921 2 Sheets-Sheet l Sept. El, B923. ll

I J.VD. MacLAcl-:LAN

ENGINE Original Filed Sent. 7. 1921 2 Sheets-Sheet 2 f7 Fa @2. l

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application med @september 7, wel, Serial No. destete. ltteneweel meant e, met.

To all whom t may concern:

Be it known that I, JOHN D. MacLAc LAN, a citizen of the United States, residing at Chadwick, in the county of Christian and State of Missouri, have invented certain new and useful Improvements in Engines, of which the following is a specification.

This invention relates to new and useful improvements in en ines of the two cycle type, the 'primary oject of the invention bein to utilize the force spent on the cylinder ead for thorou hly compressing the combustible charge a itted into the cylin- Another object of the invention is to provide a device of the above character including a piston having about one-third the displacement ofan ordinary piston whereby a smaller amount of fuel is used to run the engine without sacrifcin power produced by the reduction of the c a e.

A further object of the invention is to provide an engine embodying a pair of opposed pistons having connection with a common cra-nk shaft with the result of a quicker exhaust of the spent gases.

A still further object of the invention is to provide'an engine having a crank throw a. proximately one-half that of the pistons w ereby it is possible to obtain a long stroke motor with a small borel cylinder.

Still another object of the invention is to provide an arrangement whereby the spark plug is covered except at the instant of ignition of the combustible charge thereby providing means for eectively preventing fouling of the plug.

nother object of the invention is to provide a piston within another piston and between which the combustible charge is compressed and whereby necessity of cooling of the cylinder head is reduced to a minimum.

Other objects and advantages of the invention will become apparent during the course of the following description.

In the accompanying drawings forminor a part of the specification and wherein like numerals are employed to designate like parts throughout the several views.

Figure 1 is a vertical section through the engine illustrating the position of the various parts at the end of the exhaust stroke.

Figure 2 is a similar view taken longitudinally of the crank shaft illustrating v1 will be Seen to be slightly the positions of the various parts at the end ot' t. e compression strokes.

Figure 3 is a top plan of the crank case.

Figure 4f is a vertical section through one of the connecting rod pockets, and

Figure 5 is a section of the means for connecting the connecting rods to one of the pistons.

lln the drawings wherein for the of illustration is shown the referred embodiment of my invention, t e numeral 6 designates a crank case which 'may be of any desired shape and has its top provided with a cr-ntralv opening 7 through which the piston may pass, it being noted that openings 8 extend from diametrically opposite points of the opening to admit of connectlng rods o erating in the crank case. A crank sha i 9 1s journaled through the crank case in the ordinary manner and is equipped with three crank portions l0 within the crank case for a purpose which will presentlyl appear.

A cylinder 11 having the usual piston bore therethrough and a, lower anged end is bolted by means of bolts 12 to the top of the crank case as clearly seen. It will be noted that the bore through the cylinder extends entirely therethrough there being no top or bottom to the cylinder for closin the bore, and furthermore only the sides o? the cylinder are waterjacketed as at 13. rThe s ark plug epenin 14 extends transversely t rough t e cylin er Wall as shown as do the carburetor inlets 15 and exhaust outlets 16. As best seen in Figure 4: and Figure 2, the cylinder 1.1 is provided at diametrically opposite portions with the connecting rod pockets 1 extending longitudinally thereof and up the side of the cylinder a substantial distance.

To the top of the cylinder is bolted a surge plun er casing or chamber 18 the interior of w ich if noted carefully in Figure larger in diameter than the bore through the cylinder, this being more noticeable at the right side of the gure where the live gas is adapted to enter the bypass openings 19 as clearly seen in Figures 1 and 2. The top of the surge chamber 18 is provided with a central threaded opening adapted for the reception of a compression spring ad'uster 20, the lower end of which is provi ed with a reduced depending llange for reception in one end of the compression spring 2l located in purpose the sur e plunger chamber` 22. The other end oft e compression spring is adapted to encircle a central enlar ement formed upon a sur e plunger 23 which is providedI with peri eral packing rings to establish a wor 'n fit between the plunger and the walls o? the chamber.

The interior of the compression spring adjuster is screw threaded to receive a depending tubular threaded stem 24 o f a breather cap 25, the latter being semi-circular to thorou hly cover air openings 26 in the upper en of the tubular stem 24. Lock nuts 27 are associated with both the tubular stem 24 and the adjuster 20 so that thesetwo elements may be locked in the desired position.

y In case it is desired to vary the amountof by-passes 19.

air enterin and exhaustin from the surge chamber, t e breather cap is simply adjusted so as to vary the sizes of the opening 26 in the tubular stein. For the purpose of lubricating the surge plunger, an opening is providedv in top of the surge casing for the admission thereinto of lubricants and this opening is normally closed by its threaded plug 28 as clearly seen.

Referring more particularly to Figures 1 and 2, it will be noted that the by-passes '19 are provided with inlets and outlets, the uppermost openings being inlets and exposed so as to open into both the bore and the top portion of the cylinder 11. The lowermost openings 19 indicate the by-pass outlets and are dis osed slightly below the'inlets.

An e ongated cylinder shaped piston 29 is adapted to slide upon the walls of the bore through the cylinder 11 and has aclosed top 30 and open bottom. If desired,the exterior surface of the top 30 may be provided withv a heat conducting plate so as to cause rapid vaporization of the fuel admitted into the cylinder. The upper end of the cylinder piston 29 has its side wall equipped with a plurality of inlet openings 31, the number of which corres ond to the same number of Iy the provision of these inlet openings, a c arge may be admitted into the up er end of the cylinder iston 29 which orms the combustion cham er of the engine. Directly below the openings 31, the bore of the cylinder piston is sli htly enlarged so that an annular shoul er 32 is provided upon the interior of the piston.,

The wall of the cylinder piston 29 ,opposite the wall in which the inlet openings 31 are rovided, is equipped with an exhaust opemng 33 which correspond to the exhaust opening communicating with the exhaust port 16 inthe cylinder. It will be noted that the length of the cylinder piston is approximately the same as thelength of the cylinder and is grooved at intervals, to receive oil whereby the walls of the cylinder ma be efl'ectivel lubricated.

he walls of t e cylinder piston are pro- .vided at diametrically op ite points with a pairof laterally exten ing pintles34 as best seen in Figures 2 and 5, and upon these pintles hardened steel sleeves 36 are pressed and upon which fit the bushings 37 of connecting rods 38. It will be noted that the lower ends of the connecting rods 38 are connected to the outermost cranks 10 ofthe shaft 9 andI in order to prevent displacement of the connecting rods and steel sleeves from the pintles, a disk 39 having a central aperture therein is adapted to be clamped upon the outer ends of the pintle by means of screws 41 havin relatively broad heads and the Shanks of wghich enter central threaded openings extending longitudinally of the plntles 34. To prevent the screws 41 from turning, auxiliary screws 42 are threaded throu h the heads of the screws 41 and into the pintles. The ends of the connecting rods which are fastened to the 'pintles are bifurcated as at 43, a set screw 44 being provided to securely clamp the connecting rods to the pintles,

A piston 35 of the ordinary construction is adapted to Slide within the cylinder piston 29 from its lower end up to the shoulder 32 therein'. A wrist pin 46 journalcd in the piston forms a connection with a connecting rod 47, the lower end of which is associated with the intermediate crank 10 of the shaft 9. Having fully described the various parts of the invention, the operation of the same is as follows: First, it will be understood that while the cylinder piston 29 is moving upwardly ,to compress the charge, the piston 35 is moving downwardly to exhaust the spent ases.

As t e c linder iston 29 uncovers the carburetor in et 15, t e combustiblemixture is drawn into the upper end of the cylinder 11 and comes in contact with the surge plunger 23. About the time that this sur e plunger is about to rise by compression o? the fresh charge, the exhaust port 16 opens and as the pressure in the cylinder piston is reduced by the time the by-pass 19 opens. After the surge plunger is raised the gas mixt-ure quickly passes down in the cylinder piston with the added force of the surgeplunger returning toits normal position and incidentally forcing all burned gases ahead of it out through the exhaust. It will of course be understood that upon the compression stroke of the cylinder piston 29, the

rst charge will be compressed between the top of the (Xlinder piston and the surge plunger 23. s the pressure of the gases increases, the surge-plunger will be moved upwardly into its chamber'to make room for the compressed new charge so that when the top ofthe cylinder piston reaches and covers the uppermost inlet of the by-pass 19, the ports 31 of the cylinder piston will register with the outlet openings of the by-pass 19 lll lll

so that the compressed 4charge gas in the surge-chamber may be forced by the surgeplunger down through the by-passes into the upper end of the cylinder piston. During this operation, the piston will have covered the exhaust portion 33 and will be traveling upwardly of the cylinder 11 while the cylinder piston 29 is moving downwardly thereof whereby the charge of combustible mixture will be compressed to the highest degree in the upper part of the cylinder piston. The charge is adapted "to be fully compressed and ready for ignition as soon as the piston 35 reaches the shoulder 52 on the interior of the cylinder piston and the space between the tops of the two pistons is arrangedl opposite the spark plug positioned in the opening 14. At this time, the timing' mechanism will send a spark to the plug to ignite the charge the explosion of which will force the two pistons in opposite directions to again begin the same cycle of operations as outlined above.

The foregoing description and accompanying drawings have reference to what might be considered to be the approved or preferred form of my invention. I desire it to be understood that i may make such changes' in the construction and combination andarrangement of parts material, dimensions, etc., as may prove expedient and fall within the scope of the appended claims.

Having thus fully described my invention what i claim as new and desire to secure by Letters Patent is:

1. An engine comprising a cylinder, a surge-plunger chamber associated therewith and having a member adjustably associated with said chamber, a surge-plunger adapted for operation in said chamber, a compression spring associated with the plunger and said member, and a breather cap adjustably associated with said member for varying the amount of air entering the surge plunger chamber.

2. lin a two cycle internal combustion engine, a crank case, a cylinder carried by the crank case, a crank shaft including a plurality of throws journalled in the crank shaft, a cylinder piston operable within the cylinder, a second piston operable within the cylinder piston for ycompressing a charge therein, means for connectlng the second piston with one throw of the crank shaft, means connecting the cylinder piston with the other throws of the crank shaft, an intake port formed in the cylinder, an exhaust port formed in the cylinder, an exhaust port formed in the cylinder piston adjacent to the lower end thereof, an intake port formed in the cylinder piston adjacent to the upper end thereof, a by-path formed in the c 1inder adjacent to the upper end thereo an enlarged chamber formed in the upper end of the cylinder communicating with the -upper end of the ley-path, and a surge plunger reciprocably mounted in the enlarged portion of the chamber.

In testimony whereof I aiiix my signature in presence of two witnesses.

JOHN D. MAGLACHLAN.

Witnesses:

Rax HARRIS, ROY E. Hour. 

